Clackamas County, OR Shrink-Swell Risk

Shrink-swell potential in Clackamas County, OR

Low

Soil across 63.6% of Clackamas County, OR comes back "Low" in USDA's shrink-swell data, averaging 2.57% linear extensibility. That's the easiest starting point on this site's scale - a standard foundation is the reasonable default here, though any one lot can still differ.

What this number does and doesn't tell you

This is a countywide, area-weighted figure across every soil survey map unit in Clackamas County, OR - never a reading for one specific parcel. A site-specific soil report, usually $1,000-$5,000, is what an engineer would actually pull before designing a foundation on a lot in Clackamas County.

Clackamas County: the real numbers

Clackamas County's soil reading points toward standard foundation practice as the likely outcome, not the exception. A geotechnical report runs $1,000-$5,000, typically around $2,700. Foundation repair, if a specific lot turns out to differ from the county average, runs $5,000-$15,000.

How Clackamas County, OR compares

Among the 3,085 rated counties on this site, Clackamas County, OR ranks 1,492 most-constrained nationally, and 22 of 36 within Oregon. Clackamas County covers 1,871 square miles and counts 425,857 residents.

Before you act on this

Orleans Parish, LA carries this site's most-constrained reading. Glades County, FL and Jennings County, IN are worth a look for comparison.

How this reading is built, and its real limits · Moisture management: the cheap fix that works on any soil

Elsewhere in Oregon

Every county in Oregon is on this site, including Marion County, OR and Crook County, OR. The full underlying dataset is downloadable directly, one row per county.